diff mbox series

[ARM/FDPIC,13/21,ARM] FDPIC: Support unwinding across thumb2 signal trampoline

Message ID 20180525080354.13295-14-christophe.lyon@st.com
State New
Headers show
Series FDPIC ARM for ARM | expand

Commit Message

Christophe Lyon May 25, 2018, 8:03 a.m. UTC
2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>
	Mickaël Guêné <mickael.guene@st.com>

	libgcc/
	* unwind-arm-common.inc (FDPIC_T2_LDR_R12_WITH_FUNCDESC)
	(FDPIC_T2_LDR_R9_WITH_GOT, FDPIC_T2_LDR_PC_WITH_RESTORER): New.
	(__gnu_personality_sigframe_fdpic): Support Thumb address.
	(get_eit_entry): Support Thumb code.

Change-Id: I2bb8994e733e48a89c6f4e0682921186c086f8bc

Comments

Kyrill Tkachov June 8, 2018, 11:01 a.m. UTC | #1
Hi Christophe,

Similar comments to patch 11/21

On 25/05/18 09:03, Christophe Lyon wrote:
> 2018-XX-XX  Christophe Lyon <christophe.lyon@st.com>
>         Mickaël Guêné <mickael.guene@st.com>
>
>         libgcc/
>         * unwind-arm-common.inc (FDPIC_T2_LDR_R12_WITH_FUNCDESC)
>         (FDPIC_T2_LDR_R9_WITH_GOT, FDPIC_T2_LDR_PC_WITH_RESTORER): New.
>         (__gnu_personality_sigframe_fdpic): Support Thumb address.
>         (get_eit_entry): Support Thumb code.
>
> Change-Id: I2bb8994e733e48a89c6f4e0682921186c086f8bc
>
> diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc
> index 80d1e88..7de4033 100644
> --- a/libgcc/unwind-arm-common.inc
> +++ b/libgcc/unwind-arm-common.inc
> @@ -38,6 +38,9 @@
>  #define FDPIC_LDR_R12_WITH_FUNCDESC     0xe59fc004
>  #define FDPIC_LDR_R9_WITH_GOT           0xe59c9004
>  #define FDPIC_LDR_PC_WITH_RESTORER      0xe59cf000
> +#define FDPIC_T2_LDR_R12_WITH_FUNCDESC  0xc008f8df
> +#define FDPIC_T2_LDR_R9_WITH_GOT       0x9004f8dc
> +#define FDPIC_T2_LDR_PC_WITH_RESTORER   0xf000f8dc
>  #define FDPIC_FUNCDESC_OFFSET           12
>  /* Signal frame offsets.  */
>  #define ARM_NEW_RT_SIGFRAME_UCONTEXT    0x80
> @@ -228,7 +231,7 @@ __gnu_personality_sigframe_fdpic (_Unwind_State state,
>      _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, &sp);
>      _Unwind_VRS_Get (context, _UVRSC_CORE, R_PC, _UVRSD_UINT32, &pc);
>
> -    funcdesc = *(unsigned int *)(pc + FDPIC_FUNCDESC_OFFSET);
> +    funcdesc = *(unsigned int *)((pc & ~1) + FDPIC_FUNCDESC_OFFSET);
>      handler = *(unsigned int *)(funcdesc);
>      first_handler_instruction = *(unsigned int *)(handler & ~1);
>
> @@ -277,10 +280,13 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
>            /* If we are unwinding a signal handler then perhaps we have
>               reached a trampoline.  Try to detect jump to restorer
>               sequence.  */
> -         _uw *pc = (_uw *)((return_address+2) & ~3);
> -         if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
> -             && pc[1] == FDPIC_LDR_R9_WITH_GOT
> -             && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
> +         _uw *pc = (_uw *)((return_address+2) & ~1);
> +         if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
> +              && pc[1] == FDPIC_LDR_R9_WITH_GOT
> +              && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
> +             || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
> +                 && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
> +                 && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
>              {

This largely overwrites and extends code added in patch 11/21. Can't we just merge the two
patches into a final sane one?

Thanks,
Kyrill

>                struct funcdesc_t *funcdesc = (struct funcdesc_t *)
>                  &__gnu_personality_sigframe_fdpic;
> @@ -309,13 +315,16 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
>        /* If we are unwinding a signal handler then perhaps we have
>           reached a trampoline.  Try to detect jump to restorer
>           sequence.  */
> -      _uw *pc = (_uw *)((return_address+2) & ~3);
> -      if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
> -         && pc[1] == FDPIC_LDR_R9_WITH_GOT
> -         && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
> +      _uw *pc = (_uw *)((return_address+2) & ~1);
> +      if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
> +          && pc[1] == FDPIC_LDR_R9_WITH_GOT
> +          && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
> +         || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
> +             && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
> +             && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
>          {
> -         struct funcdesc_t *funcdesc = (struct funcdesc_t *)
> -           &__gnu_personality_sigframe_fdpic;
> +         struct funcdesc_t *funcdesc
> +           = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
>
>            UCB_PR_ADDR (ucbp) = funcdesc->ptr;
>            UCB_PR_GOT (ucbp) = funcdesc->got;
> @@ -335,13 +344,16 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
>        /* If we are unwinding a signal handler then perhaps we have
>           reached a trampoline.  Try to detect jump to restorer
>           sequence.  */
> -      _uw *pc = (_uw *)((return_address+2) & ~3);
> -      if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
> -         && pc[1] == FDPIC_LDR_R9_WITH_GOT
> -         && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
> +      _uw *pc = (_uw *)((return_address+2) & ~1);
> +      if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
> +          && pc[1] == FDPIC_LDR_R9_WITH_GOT
> +          && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
> +         || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
> +             && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
> +             && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
>          {
> -         struct funcdesc_t *funcdesc = (struct funcdesc_t *)
> -           &__gnu_personality_sigframe_fdpic;
> +         struct funcdesc_t *funcdesc
> +           = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
>
>            UCB_PR_ADDR (ucbp) = funcdesc->ptr;
>            UCB_PR_GOT (ucbp) = funcdesc->got;
> -- 
> 2.6.3
>
Christophe Lyon June 11, 2018, 6:56 a.m. UTC | #2
On 8 June 2018 at 13:01, Kyrill  Tkachov <kyrylo.tkachov@foss.arm.com> wrote:
> Hi Christophe,
>
> Similar comments to patch 11/21
>
>
> On 25/05/18 09:03, Christophe Lyon wrote:
>>
>> 2018-XX-XX  Christophe Lyon <christophe.lyon@st.com>
>>         Mickaël Guêné <mickael.guene@st.com>
>>
>>         libgcc/
>>         * unwind-arm-common.inc (FDPIC_T2_LDR_R12_WITH_FUNCDESC)
>>         (FDPIC_T2_LDR_R9_WITH_GOT, FDPIC_T2_LDR_PC_WITH_RESTORER): New.
>>         (__gnu_personality_sigframe_fdpic): Support Thumb address.
>>         (get_eit_entry): Support Thumb code.
>>
>> Change-Id: I2bb8994e733e48a89c6f4e0682921186c086f8bc
>>
>> diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc
>> index 80d1e88..7de4033 100644
>> --- a/libgcc/unwind-arm-common.inc
>> +++ b/libgcc/unwind-arm-common.inc
>> @@ -38,6 +38,9 @@
>>  #define FDPIC_LDR_R12_WITH_FUNCDESC     0xe59fc004
>>  #define FDPIC_LDR_R9_WITH_GOT           0xe59c9004
>>  #define FDPIC_LDR_PC_WITH_RESTORER      0xe59cf000
>> +#define FDPIC_T2_LDR_R12_WITH_FUNCDESC  0xc008f8df
>> +#define FDPIC_T2_LDR_R9_WITH_GOT       0x9004f8dc
>> +#define FDPIC_T2_LDR_PC_WITH_RESTORER   0xf000f8dc
>>  #define FDPIC_FUNCDESC_OFFSET           12
>>  /* Signal frame offsets.  */
>>  #define ARM_NEW_RT_SIGFRAME_UCONTEXT    0x80
>> @@ -228,7 +231,7 @@ __gnu_personality_sigframe_fdpic (_Unwind_State state,
>>      _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, &sp);
>>      _Unwind_VRS_Get (context, _UVRSC_CORE, R_PC, _UVRSD_UINT32, &pc);
>>
>> -    funcdesc = *(unsigned int *)(pc + FDPIC_FUNCDESC_OFFSET);
>> +    funcdesc = *(unsigned int *)((pc & ~1) + FDPIC_FUNCDESC_OFFSET);
>>      handler = *(unsigned int *)(funcdesc);
>>      first_handler_instruction = *(unsigned int *)(handler & ~1);
>>
>> @@ -277,10 +280,13 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw
>> return_address)
>>            /* If we are unwinding a signal handler then perhaps we have
>>               reached a trampoline.  Try to detect jump to restorer
>>               sequence.  */
>> -         _uw *pc = (_uw *)((return_address+2) & ~3);
>> -         if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
>> -             && pc[1] == FDPIC_LDR_R9_WITH_GOT
>> -             && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
>> +         _uw *pc = (_uw *)((return_address+2) & ~1);
>> +         if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
>> +              && pc[1] == FDPIC_LDR_R9_WITH_GOT
>> +              && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
>> +             || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
>> +                 && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
>> +                 && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
>>              {
>
>
> This largely overwrites and extends code added in patch 11/21. Can't we just
> merge the two
> patches into a final sane one?
>

Sure. It was developed in two steps, and I thought it was easier to
review in small pieces, but I can merge them.

> Thanks,
> Kyrill
>
>
>>                struct funcdesc_t *funcdesc = (struct funcdesc_t *)
>>                  &__gnu_personality_sigframe_fdpic;
>> @@ -309,13 +315,16 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw
>> return_address)
>>        /* If we are unwinding a signal handler then perhaps we have
>>           reached a trampoline.  Try to detect jump to restorer
>>           sequence.  */
>> -      _uw *pc = (_uw *)((return_address+2) & ~3);
>> -      if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
>> -         && pc[1] == FDPIC_LDR_R9_WITH_GOT
>> -         && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
>> +      _uw *pc = (_uw *)((return_address+2) & ~1);
>> +      if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
>> +          && pc[1] == FDPIC_LDR_R9_WITH_GOT
>> +          && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
>> +         || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
>> +             && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
>> +             && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
>>          {
>> -         struct funcdesc_t *funcdesc = (struct funcdesc_t *)
>> -           &__gnu_personality_sigframe_fdpic;
>> +         struct funcdesc_t *funcdesc
>> +           = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
>>
>>            UCB_PR_ADDR (ucbp) = funcdesc->ptr;
>>            UCB_PR_GOT (ucbp) = funcdesc->got;
>> @@ -335,13 +344,16 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw
>> return_address)
>>        /* If we are unwinding a signal handler then perhaps we have
>>           reached a trampoline.  Try to detect jump to restorer
>>           sequence.  */
>> -      _uw *pc = (_uw *)((return_address+2) & ~3);
>> -      if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
>> -         && pc[1] == FDPIC_LDR_R9_WITH_GOT
>> -         && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
>> +      _uw *pc = (_uw *)((return_address+2) & ~1);
>> +      if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
>> +          && pc[1] == FDPIC_LDR_R9_WITH_GOT
>> +          && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
>> +         || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
>> +             && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
>> +             && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
>>          {
>> -         struct funcdesc_t *funcdesc = (struct funcdesc_t *)
>> -           &__gnu_personality_sigframe_fdpic;
>> +         struct funcdesc_t *funcdesc
>> +           = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
>>
>>            UCB_PR_ADDR (ucbp) = funcdesc->ptr;
>>            UCB_PR_GOT (ucbp) = funcdesc->got;
>> --
>> 2.6.3
>>
>
diff mbox series

Patch

diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc
index 80d1e88..7de4033 100644
--- a/libgcc/unwind-arm-common.inc
+++ b/libgcc/unwind-arm-common.inc
@@ -38,6 +38,9 @@ 
 #define FDPIC_LDR_R12_WITH_FUNCDESC	0xe59fc004
 #define FDPIC_LDR_R9_WITH_GOT		0xe59c9004
 #define FDPIC_LDR_PC_WITH_RESTORER	0xe59cf000
+#define FDPIC_T2_LDR_R12_WITH_FUNCDESC  0xc008f8df
+#define FDPIC_T2_LDR_R9_WITH_GOT	0x9004f8dc
+#define FDPIC_T2_LDR_PC_WITH_RESTORER   0xf000f8dc
 #define FDPIC_FUNCDESC_OFFSET		12
 /* Signal frame offsets.  */
 #define ARM_NEW_RT_SIGFRAME_UCONTEXT	0x80
@@ -228,7 +231,7 @@  __gnu_personality_sigframe_fdpic (_Unwind_State state,
     _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, &sp);
     _Unwind_VRS_Get (context, _UVRSC_CORE, R_PC, _UVRSD_UINT32, &pc);
 
-    funcdesc = *(unsigned int *)(pc + FDPIC_FUNCDESC_OFFSET);
+    funcdesc = *(unsigned int *)((pc & ~1) + FDPIC_FUNCDESC_OFFSET);
     handler = *(unsigned int *)(funcdesc);
     first_handler_instruction = *(unsigned int *)(handler & ~1);
 
@@ -277,10 +280,13 @@  get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
 	  /* If we are unwinding a signal handler then perhaps we have
 	     reached a trampoline.  Try to detect jump to restorer
 	     sequence.  */
-	  _uw *pc = (_uw *)((return_address+2) & ~3);
-	  if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
-	      && pc[1] == FDPIC_LDR_R9_WITH_GOT
-	      && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
+	  _uw *pc = (_uw *)((return_address+2) & ~1);
+	  if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
+	       && pc[1] == FDPIC_LDR_R9_WITH_GOT
+	       && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
+	      || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
+		  && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
+		  && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
 	    {
 	      struct funcdesc_t *funcdesc = (struct funcdesc_t *)
 		&__gnu_personality_sigframe_fdpic;
@@ -309,13 +315,16 @@  get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
       /* If we are unwinding a signal handler then perhaps we have
 	 reached a trampoline.  Try to detect jump to restorer
 	 sequence.  */
-      _uw *pc = (_uw *)((return_address+2) & ~3);
-      if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
-	  && pc[1] == FDPIC_LDR_R9_WITH_GOT
-	  && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
+      _uw *pc = (_uw *)((return_address+2) & ~1);
+      if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
+	   && pc[1] == FDPIC_LDR_R9_WITH_GOT
+	   && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
+	  || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
+	      && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
+	      && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
 	{
-	  struct funcdesc_t *funcdesc = (struct funcdesc_t *)
-	    &__gnu_personality_sigframe_fdpic;
+	  struct funcdesc_t *funcdesc
+	    = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
 
 	  UCB_PR_ADDR (ucbp) = funcdesc->ptr;
 	  UCB_PR_GOT (ucbp) = funcdesc->got;
@@ -335,13 +344,16 @@  get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
       /* If we are unwinding a signal handler then perhaps we have
 	 reached a trampoline.  Try to detect jump to restorer
 	 sequence.  */
-      _uw *pc = (_uw *)((return_address+2) & ~3);
-      if (pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
-	  && pc[1] == FDPIC_LDR_R9_WITH_GOT
-	  && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
+      _uw *pc = (_uw *)((return_address+2) & ~1);
+      if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
+	   && pc[1] == FDPIC_LDR_R9_WITH_GOT
+	   && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
+	  || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
+	      && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
+	      && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
 	{
-	  struct funcdesc_t *funcdesc = (struct funcdesc_t *)
-	    &__gnu_personality_sigframe_fdpic;
+	  struct funcdesc_t *funcdesc
+	    = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
 
 	  UCB_PR_ADDR (ucbp) = funcdesc->ptr;
 	  UCB_PR_GOT (ucbp) = funcdesc->got;